Perceived Brightness Calculator - Online Luminance Formula
Calculate the perceived brightness of an RGB color and determine if black or white text is more readable. Accessibility tool.
UD5 Toolkit
Preview how your images appear to people with various types of color vision deficiency
Drop your image here
Calculate the perceived brightness of an RGB color and determine if black or white text is more readable. Accessibility tool.
Convert English text to Braille (Grade 1 and simple Grade 2 contractions). Educational tool to understand Braille representation. Local only.
Pick a base color and generate a 10‑step scale where each step meets a specific contrast ratio against white or black. Export as CSS custom properties.
Automatically restore natural colors to a photo by removing color casts. Gray world algorithm. One‑click fix. Canvas.
Enter original and target color to compute the exact CSS hue‑rotate(deg) filter needed. For precise icon and image tinting.
Start with a base color and generate an extended palette where every shade contrasts properly with white and black. Export tokens.
Pick colors using the HWB (Hue‑Whiteness‑Blackness) model. Get the CSS hwb() function code. Simpler than HSL for some.
Click colors on an interactive wheel and see the common emotions and meanings associated with them. A design resource.
Drag colored shapes to matching outlines. Simple, no-text game for 2-4 year olds. Works on touch devices.
Estimate the baby's due date based on last menstrual period (LMP) or conception date. Also shows current week and trimester. Educational only.
Request HID devices and list them. Read input reports and send output. For custom hardware and controllers.
Draw a digit (0‑9) on the canvas and a simple neural net guess the number. Educational demo. No upload.
Click any color to see common emotional associations and cultural meanings. Quick design reference.
Test the experimental Translation API to translate text between languages directly in the browser, without cloud calls. Check support and copy the JavaScript starter.
Override your browser's geolocation to any coordinates and test how your app responds. For development and privacy testing.
Paste an HTML snippet and check for common ARIA mistakes: missing labels, invalid roles, and aria‑hidden misuse. Educate your team.
Play infinite sound loops of white, pink, brown, blue, and violet noise. Volume control. Help focus or mask tinnitus.
See how a color is interpreted in different cultures (e.g., red in China vs. Western). Crucial for global web design. Static guide.
Flip a coin with adjustable bias (e.g., 70% heads). Used for random decision-making when you want to gently influence outcomes. History & stats shown.
Enter pot volume and tea type to find the right amount of dry leaf considering expansion. Avoid overflowing.
Shift the color temperature of your photo towards warm (orange) or cool (blue). Instant canvas filter. Download result.
Upload any image, add a thick white border and drop shadow, and turn it into a sticker. Download as transparent PNG.
Create a fully accessible form by adding fields; the tool generates the proper labels, inputs, and ARIA attributes. Copy the clean HTML.
Search common dream symbols and their traditional meanings. For entertainment and self-reflection. Static data.
See how a PWA can extend content into the title bar area on desktop. Customize the window controls overlay.
Add N business days to a date, skipping weekends and optionally entering custom holidays. Regional presets.
Reverse entire text, flip letters, or reverse word order. Fun for puzzles and creative writing. Instant transformation without data leaving your browser.
Convert plain text into HTML‑safe strings by escaping <, >, &, and quotes. Insert into code safely. Local copy.
Convert volume and capacity units: gallon (US/UK), liter, milliliter, cup, and fluid ounce. Handy for cooking and science. Works entirely offline.
Enter current weight and age to estimate adult weight based on growth curves. For purebred and mixed.